Factorial experiments

Experimental Design in R

Joanne Xiong

Data Scientist

Factorial designs

• 2 or more factor variables are combined and crossed
• All of the possible interactions between levels of factors are considered as effects on the outcome
  • Example: high/low water and high/low sunlight's effect on plant growth.

Factorial example

2^k factorial experiments

• 2^k factorial experiments involve k factor variables with 2 levels
• It results in 2^k number of combinations of effects to test
• Analyzed with a linear model and ANOVA
• Also use TukeyHSD() to determine which combinations are significantly different

Let's practice!

Experimental Design in R